{"id":2812,"date":"2017-05-08T09:00:27","date_gmt":"2017-05-08T13:00:27","guid":{"rendered":"http:\/\/blogs.ams.org\/blogonmathblogs\/?p=2812"},"modified":"2017-05-05T13:12:37","modified_gmt":"2017-05-05T17:12:37","slug":"cooks-take-on-benford","status":"publish","type":"post","link":"https:\/\/blogs.ams.org\/blogonmathblogs\/2017\/05\/08\/cooks-take-on-benford\/","title":{"rendered":"Cook&#8217;s Take on Benford"},"content":{"rendered":"<div id=\"attachment_2826\" style=\"width: 1290px\" class=\"wp-caption alignright\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2826\" src=\"https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/1280px-Tallest_buildings_in_the_world.png?resize=640%2C254\" alt=\"\" width=\"640\" height=\"254\" class=\"size-full wp-image-2826\" srcset=\"https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/1280px-Tallest_buildings_in_the_world.png?w=1280&amp;ssl=1 1280w, https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/1280px-Tallest_buildings_in_the_world.png?resize=300%2C119&amp;ssl=1 300w, https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/1280px-Tallest_buildings_in_the_world.png?resize=768%2C305&amp;ssl=1 768w, https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/1280px-Tallest_buildings_in_the_world.png?resize=1024%2C406&amp;ssl=1 1024w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><p id=\"caption-attachment-2826\" class=\"wp-caption-text\">The leading digits of the heights of the world&#8217;s tallest buildings satisfy Benford&#8217;s Law.<\/p><\/div>\n<p>Lately, I&#8217;ve been having fun reading <a href=\"https:\/\/www.johndcook.com\/blog\/services-2\/\">John D Cook&#8217;s Blog<\/a>. Cook is an applied mathematics consultant who blogs and tweets up a storm about all sorts of topics mathematical, statistical, computational, and scientific. He maintains <a href=\"https:\/\/www.johndcook.com\/blog\/twitter_page\/\">18 daily tip Twitter feeds<\/a> giving daily facts about&#8230;well, everything&#8230;and one personal feed.  <\/p>\n<div id=\"attachment_2815\" style=\"width: 160px\" class=\"wp-caption alignright\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-2815\" src=\"https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/512px-Rozklad_benforda.svg_.png?resize=150%2C150\" alt=\"\" width=\"150\" height=\"150\" class=\"size-thumbnail wp-image-2815\" srcset=\"https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/512px-Rozklad_benforda.svg_.png?resize=150%2C150&amp;ssl=1 150w, https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/512px-Rozklad_benforda.svg_.png?zoom=2&amp;resize=150%2C150 300w, https:\/\/i0.wp.com\/blogs.ams.org\/blogonmathblogs\/files\/2017\/05\/512px-Rozklad_benforda.svg_.png?zoom=3&amp;resize=150%2C150 450w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><p id=\"caption-attachment-2815\" class=\"wp-caption-text\">A leading digit 1 is expected to appear a whopping 30% of the time.<\/p><\/div>\n<p>But what I like most are his mathematical blog posts.  He writes short easy to digest posts about reasonably accessible topics in math, often with a computational bent, and I always walk away feeling like I learned something.  This past week he revisited the topic of <a href=\"https:\/\/en.wikipedia.org\/wiki\/Benford%27s_law\">Benford&#8217;s law<\/a>, which is this totally weird and strange thing that I&#8217;ve always wanted to understand more about. Benford&#8217;s law says that in many naturally occurring data sets the leading digit is more likely to be small.  If the leading digit <em>d<\/em> from the set <em>{1,&#8230;,9}<\/em> were distributed uniformly you would expect each digit to show up about 11.1% of the time.  But in reality, the leading digit is more often distributed according to the chart on the right. Cook can fill you in on some of the <a href=\"https:\/\/www.johndcook.com\/blog\/2011\/10\/19\/benfords-law-and-scipy\/\">more precise formulations of Benford&#8217;s Law<\/a>. <\/p>\n<p>In his blog, Cook describes how <a href=\"https:\/\/www.johndcook.com\/blog\/2011\/10\/19\/leading-digits-of-factorials\/\">the leading digits of factorials satisfy Bedford&#8217;s Law<\/a>, and even gives some tips on how you can use Python to compute leading digits up to 500!! (One of those exclamations is a factorial, the other one is for my excitement.)  He also show that the collection of <a href=\"https:\/\/docs.scipy.org\/doc\/scipy-0.19.0\/reference\/constants.html\">SciPy constants<\/a> follow Benford&#8217;s Law, which <a href=\"https:\/\/www.johndcook.com\/blog\/2011\/10\/19\/benfords-law-and-scipy\/\">Cook explains and computes using Python<\/a>. Cook blogged about how samples from the <a href=\"https:\/\/www.johndcook.com\/blog\/2017\/05\/02\/weibull-distribution-and-benfords-law\/\">Weibull distribution satisfy Benford&#8217;s Law<\/a>, and most recently he even showed that the iterates of the <a href=\"https:\/\/www.johndcook.com\/blog\/\">Collatz conjecture seem to follow Benford&#8217;s Law<\/a>.  <\/p>\n<p>And you know a party is getting good <a href=\"https:\/\/xkcd.com\/710\/\">when the Collatz Conjecture shows up<\/a>. <\/p>\n<p>These posts just give a small flavor of Cook&#8217;s writing.  I also really enjoyed his recent posts on <a href=\"https:\/\/www.johndcook.com\/blog\/2017\/04\/18\/computing-harmonic-numbers\/\">harmonic numbers<\/a> and <a href=\"https:\/\/www.johndcook.com\/blog\/2017\/05\/01\/golden-angle\/\">golden angles<\/a> (largely because it prompted me to check out the work of the visual artist <a href=\"http:\/\/www.johnedmark.com\">John Edmark<\/a>), the lesser known cousin of the golden ratio.<\/p>\n<div style=\"margin-top: 0px; margin-bottom: 0px;\" class=\"sharethis-inline-share-buttons\" ><\/div>","protected":false},"excerpt":{"rendered":"<p>Lately, I&#8217;ve been having fun reading John D Cook&#8217;s Blog. Cook is an applied mathematics consultant who blogs and tweets up a storm about all sorts of topics mathematical, statistical, computational, and scientific. He maintains 18 daily tip Twitter feeds &hellip; <a href=\"https:\/\/blogs.ams.org\/blogonmathblogs\/2017\/05\/08\/cooks-take-on-benford\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n<div style=\"margin-top: 0px; margin-bottom: 0px;\" class=\"sharethis-inline-share-buttons\" data-url=https:\/\/blogs.ams.org\/blogonmathblogs\/2017\/05\/08\/cooks-take-on-benford\/><\/div>\n","protected":false},"author":69,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2812","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p3tW3N-Jm","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/posts\/2812","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/users\/69"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/comments?post=2812"}],"version-history":[{"count":17,"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/posts\/2812\/revisions"}],"predecessor-version":[{"id":2831,"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/posts\/2812\/revisions\/2831"}],"wp:attachment":[{"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/media?parent=2812"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/categories?post=2812"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.ams.org\/blogonmathblogs\/wp-json\/wp\/v2\/tags?post=2812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}